The present invention relates to electrical connectors, and in particular to an electrical connector providing a means for establishing an automatic grounded termination point for the connector upon disconnection of the connector from an external signal source or receiving device.
In the transmission of radio frequency (RF) signals, it is undesirable to have unterminated or open connectors when the electrical connection to an external signal source or receiving device is broken, due to the potential that spurious extraneous signals, undesired signal emissions and signal reflections have for causing interference when circuitry termination points are left exposed and ungrounded. Because they are ungrounded, unterminated or open connectors allow the emission of such stray signals and cause unwanted signal reflection within the system. To eliminate this problem, the present invention provides a simple and inexpensive connector which can be automatically terminated to ground whenever it is disconnected from a mating connector.
Accordingly, it is an object of the present invention to provide an electrical connector to eliminate the effects of spurious extraneous signals, undesired signal emissions and signal reflections on the circuitry connected to the connector.
It is an additional object of the present invention to provide a simple and inexpensive connector which can be automatically terminated whenever it is disconnected from a mating connector.
It is an additional object of the present invention to provide electrical connector having means for establishing an automatic grounded termination point for the connector upon disconnection of the connector from an external signal source or receiving device.
The connector of the present invention is preferably comprised of an exterior shell made of a material with sufficiently high electrical conductivity and mechanical strength to permit mounting the connector to various types of mating connectors and other electrical devices as well as to act as a housing for the other components making up the connector. A lining made of an electrically insulating material is inserted into the shell. This lining mechanically secures and electronically isolates the shell from a center conductor located within the connector. The shell also serves as the means by which the electrical connection to ground is established for the self-termination feature of the invention.
One end of the exterior shell is preferably configured to be mounted to a circuit board, to a male or female coaxial F connector, or to any other signal carrying device or connector to permit establishing a semi-permanent connection between the connector and the device to which it is mounted. The other end of the exterior shell is preferably configured to establish a removable connection with a male coaxial F connector, BNC connector or any other similarly designed connector.
The center conductor is made of an electrically conductive material preferably having a spring characteristic. The center conductor can be made in a one piece or a two-piece fabrication. One end of the conductor is configured to be connected to a circuit board, to a male or female coaxial F connector, or to the signal carrying wire of any other signal carrying device or connector to establish a semi-permanent connection with the device to which the connector is mounted. The other end of the center conductor is configured to accomplish the self-termination feature of the present invention. This self-terminating end of the conductor preferably consists of at least two separable contactor pieces which are configured to have the tendency to be forced together in the absence of an external connection. The contactor pieces preferably contain at least two sets of tabs which are preferably angled such that they are forced together under spring-like pressure to form two wedges. In the absence of an external conductor element from another electrical device or connector, the wedge formed by one of the tab pairs holds a resistive element outward against the inside of the grounded exterior shell to provide an electrical connection between the center conductor and the exterior shell through a resistive element. Insertion of an external conductor element from another electrical device or connector into the wedge formed by the other set of tab pairs forces the contactor pieces to spread, thereby causing the center conductor to become ungrounded by breaking either the electrical connection between the resistive element and the center conductor or the connection between the resistive element and the exterior shell. The breaking of this ground connection allows a normal electrical connection to be established between the inserted external conductor element and the device to which the connector is mounted.
Also, a capacitive material can optionally be placed in series with the grounding resistive element assembly to block direct current to the resistive element in its grounded state that would otherwise overheat and damage the electrical resistor material.
Other details, objects, and advantages of the present invention will become apparent in the following description of the presently preferred embodiments.